I tried searching things about horn woofers but didn't find that much specific information about them. Still it seems like some people here have tried and used them.

I've been wrestling around this system configuration. I have a MTM top cabinet standing by and it can handle down to 150-200Hz with cardioid radiation pattern using acoustic resistance solution. But I don't know what to use below that. Cross also seems pretty high to stack couple of standard monopole subwoofers with them as well.

But what about horns. I know the basic theory about them and seems like folding with floor + front wall placement helps with the size issue.

Dipole could work in my case but since the listeningroom is pretty small in listening direction its not easy to obtain enough space behind the dipolebass. One issue is also the trouble of having enough "slam" from decent size dipole.

So, could horn woofer solution be the one for me?

Personally I don't need that high efficiency and 120dB and such SPL ratings are also way too much. Range could be something like 50-200Hz, easy to pick up the bottom with regular subwoofer and have enough breathingspace for top system in the upper end.

What size of driver should I start looking for, how large horn structure do I need for such placement and are these thoughts even realistic?

Another question is about the top end. Do I really need that MTM AR cabinet with relatively poor effieciency (rear radiation is eating away front radiation to obtain needed radiation pattern) or could I just drop off that MTM idea and just use single mid in decent size horn to play 200-2000Hz range or so? And how usable my present Seas W18E001 midwoofers would be in such horn application?

Thanks in advance! This is whole new territory for me so sorry about the dumb questions.